1. Field of the Invention
The present invention relates to sewing machine and more particularly to a sewing machine having a machine body and a wireless controller provided independently of the machine body.
2. Description of Related Art
Conventionally, a wireless foot controller for a sewing machine having a pedal is known. The foot controller transmits an operating speed command, corresponding to an amount the pedal is depressed, to a control device provided in the machine body that adjusts the operating speed of the machine.
In such a foot controller, a battery is generally used as the power source. Accordingly, when the battery is at the end of its useful life, resulting in a reduction in output voltage, the transmission of the operating speed command becomes unstable, and finally, no longer occurs. As a result, the machine malfunctions by running continually and cannot be stopped and the speed cannot be changed because the signal cannot be transmitted. As a needle reciprocates during operation of the sewing machine, any malfunction, such as the runaway machine is very dangerous to an operator and could result in an accident.